CVE-2026-31407
CVE-2026-31407 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.
Key facts
- Severity: High (CVSS 3.x base score 7.1)
- EPSS exploit prediction: 0% (7th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-19197
- Weakness: CWE-787
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: add missing netlink policy validations Hyunwoo Kim reports out-of-bounds access in sctp and ctnetlink. These attributes are used by the kernel without any validation. Extend the netlink policies accordingly. Quoting the reporter: nlattr_to_sctp() assigns the user-supplied CTA_PROTOINFO_SCTP_STATE value directly to ct->proto.sctp.state without checking that it is within the valid range. [..] and: ... with exp->dir = 100, the access at ct->master->tuplehash[100] reads 5600 bytes past the start of a 320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by UBSAN.
Frequently asked questions
- What is CVE-2026-31407?
- In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: add missing netlink policy validations Hyunwoo Kim reports out-of-bounds access in sctp and ctnetlink. These attributes are used by the kernel without any validation. Extend the netlink policies accordingly. Quoting the reporter: nlattr_to_sctp() assigns the user-supplied CTA_PROTOINFO_SCTP_STATE value directly to ct->proto.sctp.state without checking that it is within the valid range. [..] and: ... with exp->dir = 100, the access at ct->master->tuplehash[100] reads 5600 bytes past the start of a 320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by UBSAN.
- How severe is CVE-2026-31407?
- CVE-2026-31407 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
- Is CVE-2026-31407 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-31407?
- CVE-2026-31407 primarily affects Linux Linux Kernel. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2026-31407?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-31407 have an EU (EUVD) identifier?
- Yes. CVE-2026-31407 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19197.
- When was CVE-2026-31407 published?
- CVE-2026-31407 was published on 2026-04-06 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/0fbae1e74493d5a160a70c51aeba035d8266ea7d
- https://git.kernel.org/stable/c/67c53c1978cef3c504237275e39c857e2f6af56e
- https://git.kernel.org/stable/c/78bba9f73942aa7dca47d817d8cec0fb9b443b70
- https://git.kernel.org/stable/c/9174d28f3f15d8c4962f5980c0be167633880443
- https://git.kernel.org/stable/c/be88a337bf07afb1ee173f1099294d1b7ab3fefe
- https://git.kernel.org/stable/c/c5e918390002edf0cff80a0e7ce1f86f16a9507c
- https://git.kernel.org/stable/c/e7b5766693477c52424cc6c79dd30a7a9c7db52c
- https://git.kernel.org/stable/c/f900e1d77ee0ef87bfb5ab3fe60f0b3d8ad5ba05
Affected products (5)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
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